I had what seems like a similar problem with my 635csi. Turns out that the guibo was bad, but I don't even know if the 750 uses guibos. Another possible cause could be a cracked differential mount (i had this happen too). My mechanic is very honest and very good - Grant Randall at Alexandria Bavarian Service (703) 836-2002. Please mention me if you talk to him, maybe he'll give me a discount on my next visit (yeah, right).

Troy Kimmel'86 635csi (looking for an E32 735i)

My 91 750 vibrates at take off and stops around 25mph. The vibration SEEMS to be coming from the rear passenger side.

From reading the forum, a lot of people have had problems with center u-joints. I went to the dealer today and they seem to think it's my drive shaft and differential to the tune of over $4000. I think it could be the drive shaft but not the differential because there is no slippage.

Does anyone know of a part source for drive shafts and u-joints and maybe a possible differential?

Lastly, does anyone know of a good/honest 750 mechanic in the Washington DC/Richmond area?